Background: Histoplasmosis is caused by Histoplasma capsulatum which can lead to a broad spectrum of disease. Culture remains the gold standard till date, however, this is a slow growing fungus which may take a considerable time before a conclusion could be made. This case highlights the importance of careful bone marrow evaluation to identify the fungal bodies especially in the presence of increase hemophagocytic activity. Case presentation: We present a 36-year-old man with newly diagnosed retroviral disease, presented with fever, pancytopenia and hepatosplenomegaly. Bone marrow aspirate smear show increase hemophagocytic activity with presence of intracellular organism. Trephine biopsy showed similar features with presence of fungal bodies detected via PAS stain. Conclusion: In conclusion, bone marrow examination plays a crucial role in the diagnosis of some fungal infections, especially in centers where culture and serological tests are not readily available.

Keywords: Histoplasma capsulatum, Histoplasmosis, HLH, hemophagocytosis, pancytopenia, case report